Apatite (more precisely, Fluorapatite), fluorinated calcium phosphate, formula Ca5(PO4)3F.

Crystal system: Hexagonal
Hardness: 5
Density: 3.2 gms/cm3
Colour: Yellow, grey, blue-green, violet-blue or brown. Also colourless.
Streak: Colourless or white

Apatite is a generic name applied to three types of Apatite; Fluorapatite, Hydroxylapatite ((OH) replacing F) and Chlorapatite (Cl replacing F). A solid solution exists between all three end members. Apatite is a principal Phosphate ore and is widespread.

The largest known deposit of Apatite is Kirovsk in the Kola Peninsula, Russia,

The specimen shown is from Gav Valadare, Minas Gerais, Brazil.

Apatite, Gav Valadare, Minas Gerais, Brazil.